UT Southwestern researcher studies fat-burning mouse hormone

by John P. Meyer

Thank God for mice, and also for Dr. Steven Kliewer, professor of molecular biology and pharmacology at UT Southwestern Medical Center. In a glowing example of cross-species cooperation, the mice are busy producing a hormone called (drum roll, please) "fibroblast growth factor 21," while the good doctor is studying the effects of said hormone on mouse physiology - with an eye toward eventual applications on the human side of the genetic fence.

In a mouse-sized nutshell, this FGF21 stuff is produced by starving mice. A primary effect seems to be that a mouse under its influence starts burning stored fat as opposed to carbohydrates. We can easily imagine how this might apply to those concerned with weight-loss.

Another notable effect of the hormone is a decrease in body temperature and physical activity - in other words, it induces a kind of hibernation.

The breakthrough came when properly-fed lab mice (not to be confused with lab rats) were given FGF21. Per Dr. Kliewer, "when the mice were given this hormone, their metabolism appeared as if they were starved, even after they had just eaten." In other words, they started burning stored body fat - and becoming sluggish.

It's not clear how the metabolic slowdown part of the effect envelope might prove beneficial to the behavior of obese humans, so perhaps the scientists can find a way to split off this side effect and provide "fibroblast sloth factor 22" pills to the Type A personality folks who try to drive 90 on LBJ through rush hour traffic. Oh, and dispense a brisk kick in the balls while they're at it.